Tire question for SCCA racers

[dallasdude]

Roger Krause is the guy to buy Avons from....with might be fastest of all but no contingency program in the US.

 

I staggered front to back sizes last year with radial slicks, but probably not worth the trouble. Never did with bias. You probably don't want a taller tire in the back anyway. Gearing.

 

I see you have five choices from Hoosier. People tried the formula car tires several years ago and they are designed for a thousand pound car not a 1500 pound car, although I am not sure what the fast FP seven used at the runoffs at Laguna Seca.

Sizes and Hoosier part number

P185/60ZR13 46301

P205/60ZR13 46306

These are DOT radials and R7's are approaching the speed of the true racing tires. You can buy from Tire Rack and anyone can mount them.

190/530R13 43548

215/530R13 43549

Radial slicks These are expensive tires and are more difficult to mount. Buy from race tire dealers

20/8/13 43171

Cantilever bias slick. Takes the right machine and tire buster to mount. Buy from race tire dealers.

 

Verify, but I believe all these tires are approved for a 6" wheel. I really think there is only a spread of 1-2 seconds from the fastest to the slowest tire....but fastest being the bias slick but at the end of a 40 minute race that has mostly gone away.

 

The radials will require more camber in the front (simple realignment) and ideally different camber ears in the back.

 

Hoosier has a several distributors in the Midwest, who in turn sell to dealers.

 

If I wanted to just have a good time on track days....I'd buy the DOT radials....do a simple alignment in the front and call it a day. Big tires don't always mean faster lap times.

[Kitcat]

Thx DD, that's exactly the info I needed!

[dallasdude]

For track use only with the radials, on the front, I would put in about 2.5 degrees negative camber and a just a very small amount of toe out. Caster is not very adjustable but you want the max available and for it be equal sided to side.

 

In the rear, you can shim or replace the dedion ears for additional camber, and you want a very small amount of toe in. I think with the stock old style camber plates, you get less than an degree of negative camber. The theory here is more negative camber is better also for redials, but now sure it adds much speed and it sure wears out the inside of your tires faster.